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  1. /*
  2.  * Copyright (c) 2006 Ondrej Palkovsky
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericipc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. /* Lock ordering
  36.  *
  37.  * First the answerbox, then the phone.
  38.  */
  39.  
  40. #include <synch/spinlock.h>
  41. #include <synch/waitq.h>
  42. #include <synch/synch.h>
  43. #include <ipc/ipc.h>
  44. #include <errno.h>
  45. #include <mm/slab.h>
  46. #include <arch.h>
  47. #include <proc/task.h>
  48. #include <memstr.h>
  49. #include <debug.h>
  50.  
  51. #include <print.h>
  52. #include <proc/thread.h>
  53. #include <arch/interrupt.h>
  54. #include <ipc/irq.h>
  55.  
  56. /** Open channel that is assigned automatically to new tasks */
  57. answerbox_t *ipc_phone_0 = NULL;
  58.  
  59. static slab_cache_t *ipc_call_slab;
  60.  
  61. /** Initialize a call structure.
  62.  *
  63.  * @param call      Call structure to be initialized.
  64.  */
  65. static void _ipc_call_init(call_t *call)
  66. {
  67.     memsetb((uintptr_t) call, sizeof(*call), 0);
  68.     call->callerbox = &TASK->answerbox;
  69.     call->sender = TASK;
  70.     call->buffer = NULL;
  71. }
  72.  
  73. /** Allocate and initialize a call structure.
  74.  *
  75.  * The call is initialized, so that the reply will be directed to
  76.  * TASK->answerbox.
  77.  *
  78.  * @param flags     Parameters for slab_alloc (e.g FRAME_ATOMIC).
  79.  *
  80.  * @return      If flags permit it, return NULL, or initialized kernel
  81.  *          call structure.
  82.  */
  83. call_t *ipc_call_alloc(int flags)
  84. {
  85.     call_t *call;
  86.  
  87.     call = slab_alloc(ipc_call_slab, flags);
  88.     _ipc_call_init(call);
  89.  
  90.     return call;
  91. }
  92.  
  93. /** Initialize a statically allocated call structure.
  94.  *
  95.  * @param call      Statically allocated kernel call structure to be
  96.  *          initialized.
  97.  */
  98. void ipc_call_static_init(call_t *call)
  99. {
  100.     _ipc_call_init(call);
  101.     call->flags |= IPC_CALL_STATIC_ALLOC;
  102. }
  103.  
  104. /** Deallocate a call structure.
  105.  *
  106.  * @param call      Call structure to be freed.
  107.  */
  108. void ipc_call_free(call_t *call)
  109. {
  110.     ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
  111.     /* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
  112.     if (call->buffer)
  113.         free(call->buffer);
  114.     slab_free(ipc_call_slab, call);
  115. }
  116.  
  117. /** Initialize an answerbox structure.
  118.  *
  119.  * @param box       Answerbox structure to be initialized.
  120.  */
  121. void ipc_answerbox_init(answerbox_t *box)
  122. {
  123.     spinlock_initialize(&box->lock, "ipc_box_lock");
  124.     spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
  125.     waitq_initialize(&box->wq);
  126.     list_initialize(&box->connected_phones);
  127.     list_initialize(&box->calls);
  128.     list_initialize(&box->dispatched_calls);
  129.     list_initialize(&box->answers);
  130.     list_initialize(&box->irq_notifs);
  131.     list_initialize(&box->irq_head);
  132.     box->task = TASK;
  133. }
  134.  
  135. /** Connect a phone to an answerbox.
  136.  *
  137.  * @param phone     Initialized phone structure.
  138.  * @param box       Initialized answerbox structure.
  139.  */
  140. void ipc_phone_connect(phone_t *phone, answerbox_t *box)
  141. {
  142.     spinlock_lock(&phone->lock);
  143.  
  144.     phone->state = IPC_PHONE_CONNECTED;
  145.     phone->callee = box;
  146.  
  147.     spinlock_lock(&box->lock);
  148.     list_append(&phone->link, &box->connected_phones);
  149.     spinlock_unlock(&box->lock);
  150.  
  151.     spinlock_unlock(&phone->lock);
  152. }
  153.  
  154. /** Initialize a phone structure.
  155.  *
  156.  * @param phone     Phone structure to be initialized.
  157.  */
  158. void ipc_phone_init(phone_t *phone)
  159. {
  160.     spinlock_initialize(&phone->lock, "phone_lock");
  161.     phone->callee = NULL;
  162.     phone->state = IPC_PHONE_FREE;
  163.     atomic_set(&phone->active_calls, 0);
  164. }
  165.  
  166. /** Helper function to facilitate synchronous calls.
  167.  *
  168.  * @param phone     Destination kernel phone structure.
  169.  * @param request   Call structure with request.
  170.  */
  171. void ipc_call_sync(phone_t *phone, call_t *request)
  172. {
  173.     answerbox_t sync_box;
  174.  
  175.     ipc_answerbox_init(&sync_box);
  176.  
  177.     /* We will receive data in a special box. */
  178.     request->callerbox = &sync_box;
  179.  
  180.     ipc_call(phone, request);
  181.     ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
  182. }
  183.  
  184. /** Answer a message which was not dispatched and is not listed in any queue.
  185.  *
  186.  * @param call      Call structure to be answered.
  187.  */
  188. static void _ipc_answer_free_call(call_t *call)
  189. {
  190.     answerbox_t *callerbox = call->callerbox;
  191.  
  192.     call->flags |= IPC_CALL_ANSWERED;
  193.  
  194.     spinlock_lock(&callerbox->lock);
  195.     list_append(&call->link, &callerbox->answers);
  196.     spinlock_unlock(&callerbox->lock);
  197.     waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
  198. }
  199.  
  200. /** Answer a message which is in a callee queue.
  201.  *
  202.  * @param box       Answerbox that is answering the message.
  203.  * @param call      Modified request that is being sent back.
  204.  */
  205. void ipc_answer(answerbox_t *box, call_t *call)
  206. {
  207.     /* Remove from active box */
  208.     spinlock_lock(&box->lock);
  209.     list_remove(&call->link);
  210.     spinlock_unlock(&box->lock);
  211.     /* Send back answer */
  212.     _ipc_answer_free_call(call);
  213. }
  214.  
  215. /** Simulate sending back a message.
  216.  *
  217.  * Most errors are better handled by forming a normal backward
  218.  * message and sending it as a normal answer.
  219.  *
  220.  * @param phone     Phone structure the call should appear to come from.
  221.  * @param call      Call structure to be answered.
  222.  * @param err       Return value to be used for the answer.
  223.  */
  224. void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
  225. {
  226.     call->data.phone = phone;
  227.     atomic_inc(&phone->active_calls);
  228.     IPC_SET_RETVAL(call->data, err);
  229.     _ipc_answer_free_call(call);
  230. }
  231.  
  232. /** Unsafe unchecking version of ipc_call.
  233.  *
  234.  * @param phone     Phone structure the call comes from.
  235.  * @param box       Destination answerbox structure.
  236.  */
  237. static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
  238. {
  239.     if (!(call->flags & IPC_CALL_FORWARDED)) {
  240.         atomic_inc(&phone->active_calls);
  241.         call->data.phone = phone;
  242.     }
  243.  
  244.     spinlock_lock(&box->lock);
  245.     list_append(&call->link, &box->calls);
  246.     spinlock_unlock(&box->lock);
  247.     waitq_wakeup(&box->wq, WAKEUP_FIRST);
  248. }
  249.  
  250. /** Send an asynchronous request using a phone to an answerbox.
  251.  *
  252.  * @param phone     Phone structure the call comes from and which is
  253.  *          connected to the destination answerbox.
  254.  * @param call      Call structure with request.
  255.  *
  256.  * @return      Return 0 on success, ENOENT on error.
  257.  */
  258. int ipc_call(phone_t *phone, call_t *call)
  259. {
  260.     answerbox_t *box;
  261.  
  262.     spinlock_lock(&phone->lock);
  263.     if (phone->state != IPC_PHONE_CONNECTED) {
  264.         spinlock_unlock(&phone->lock);
  265.         if (call->flags & IPC_CALL_FORWARDED) {
  266.             IPC_SET_RETVAL(call->data, EFORWARD);
  267.             _ipc_answer_free_call(call);
  268.         } else {
  269.             if (phone->state == IPC_PHONE_HUNGUP)
  270.                 ipc_backsend_err(phone, call, EHANGUP);
  271.             else
  272.                 ipc_backsend_err(phone, call, ENOENT);
  273.         }
  274.         return ENOENT;
  275.     }
  276.     box = phone->callee;
  277.     _ipc_call(phone, box, call);
  278.    
  279.     spinlock_unlock(&phone->lock);
  280.     return 0;
  281. }
  282.  
  283. /** Disconnect phone from answerbox.
  284.  *
  285.  * This call leaves the phone in the HUNGUP state. The change to 'free' is done
  286.  * lazily later.
  287.  *
  288.  * @param phone     Phone structure to be hung up.
  289.  *              
  290.  * @return      Return 0 if the phone is disconnected.
  291.  *          Return -1 if the phone was already disconnected.
  292.  */
  293. int ipc_phone_hangup(phone_t *phone)
  294. {
  295.     answerbox_t *box;
  296.     call_t *call;
  297.    
  298.     spinlock_lock(&phone->lock);
  299.     if (phone->state == IPC_PHONE_FREE ||
  300.         phone->state == IPC_PHONE_HUNGUP ||
  301.         phone->state == IPC_PHONE_CONNECTING) {
  302.         spinlock_unlock(&phone->lock);
  303.         return -1;
  304.     }
  305.     box = phone->callee;
  306.     if (phone->state != IPC_PHONE_SLAMMED) {
  307.         /* Remove myself from answerbox */
  308.         spinlock_lock(&box->lock);
  309.         list_remove(&phone->link);
  310.         spinlock_unlock(&box->lock);
  311.  
  312.         if (phone->state != IPC_PHONE_SLAMMED) {
  313.             call = ipc_call_alloc(0);
  314.             IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
  315.             call->flags |= IPC_CALL_DISCARD_ANSWER;
  316.             _ipc_call(phone, box, call);
  317.         }
  318.     }
  319.  
  320.     phone->state = IPC_PHONE_HUNGUP;
  321.     spinlock_unlock(&phone->lock);
  322.  
  323.     return 0;
  324. }
  325.  
  326. /** Forwards call from one answerbox to another one.
  327.  *
  328.  * @param call      Call structure to be redirected.
  329.  * @param newphone  Phone structure to target answerbox.
  330.  * @param oldbox    Old answerbox structure.
  331.  *
  332.  * @return      Return 0 if forwarding succeeded or an error code if
  333.  *          there was error.
  334.  *
  335.  * The return value serves only as an information for the forwarder,
  336.  * the original caller is notified automatically with EFORWARD.
  337.  */
  338. int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
  339. {
  340.     spinlock_lock(&oldbox->lock);
  341.     list_remove(&call->link);
  342.     spinlock_unlock(&oldbox->lock);
  343.  
  344.     return ipc_call(newphone, call);
  345. }
  346.  
  347.  
  348. /** Wait for a phone call.
  349.  *
  350.  * @param box       Answerbox expecting the call.
  351.  * @param usec      Timeout in microseconds. See documentation for
  352.  *          waitq_sleep_timeout() for decription of its special
  353.  *          meaning.
  354.  * @param flags     Select mode of sleep operation. See documentation for
  355.  *          waitq_sleep_timeout() for description of its special
  356.  *          meaning.
  357.  * @return      Recived call structure or NULL.
  358.  *
  359.  * To distinguish between a call and an answer, have a look at call->flags.
  360.  */
  361. call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
  362. {
  363.     call_t *request;
  364.     ipl_t ipl;
  365.     int rc;
  366.  
  367. restart:
  368.     rc = waitq_sleep_timeout(&box->wq, usec, flags);
  369.     if (SYNCH_FAILED(rc))
  370.         return NULL;
  371.    
  372.     spinlock_lock(&box->lock);
  373.     if (!list_empty(&box->irq_notifs)) {
  374.         ipl = interrupts_disable();
  375.         spinlock_lock(&box->irq_lock);
  376.  
  377.         request = list_get_instance(box->irq_notifs.next, call_t, link);
  378.         list_remove(&request->link);
  379.  
  380.         spinlock_unlock(&box->irq_lock);
  381.         interrupts_restore(ipl);
  382.     } else if (!list_empty(&box->answers)) {
  383.         /* Handle asynchronous answers */
  384.         request = list_get_instance(box->answers.next, call_t, link);
  385.         list_remove(&request->link);
  386.         atomic_dec(&request->data.phone->active_calls);
  387.     } else if (!list_empty(&box->calls)) {
  388.         /* Handle requests */
  389.         request = list_get_instance(box->calls.next, call_t, link);
  390.         list_remove(&request->link);
  391.         /* Append request to dispatch queue */
  392.         list_append(&request->link, &box->dispatched_calls);
  393.     } else {
  394.         /* This can happen regularly after ipc_cleanup */
  395.         spinlock_unlock(&box->lock);
  396.         goto restart;
  397.     }
  398.     spinlock_unlock(&box->lock);
  399.     return request;
  400. }
  401.  
  402. /** Answer all calls from list with EHANGUP answer.
  403.  *
  404.  * @param lst       Head of the list to be cleaned up.
  405.  */
  406. static void ipc_cleanup_call_list(link_t *lst)
  407. {
  408.     call_t *call;
  409.  
  410.     while (!list_empty(lst)) {
  411.         call = list_get_instance(lst->next, call_t, link);
  412.         list_remove(&call->link);
  413.  
  414.         IPC_SET_RETVAL(call->data, EHANGUP);
  415.         _ipc_answer_free_call(call);
  416.     }
  417. }
  418.  
  419. /** Cleans up all IPC communication of the current task.
  420.  *
  421.  * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
  422.  * have to change it as well if you want to cleanup other tasks than TASK.
  423.  */
  424. void ipc_cleanup(void)
  425. {
  426.     int i;
  427.     call_t *call;
  428.     phone_t *phone;
  429.     DEADLOCK_PROBE_INIT(p_phonelck);
  430.  
  431.     /* Disconnect all our phones ('ipc_phone_hangup') */
  432.     for (i = 0; i < IPC_MAX_PHONES; i++)
  433.         ipc_phone_hangup(&TASK->phones[i]);
  434.  
  435.     /* Disconnect all connected irqs */
  436.     ipc_irq_cleanup(&TASK->answerbox);
  437.  
  438.     /* Disconnect all phones connected to our answerbox */
  439. restart_phones:
  440.     spinlock_lock(&TASK->answerbox.lock);
  441.     while (!list_empty(&TASK->answerbox.connected_phones)) {
  442.         phone = list_get_instance(TASK->answerbox.connected_phones.next,
  443.             phone_t, link);
  444.         if (!spinlock_trylock(&phone->lock)) {
  445.             spinlock_unlock(&TASK->answerbox.lock);
  446.             DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
  447.             goto restart_phones;
  448.         }
  449.        
  450.         /* Disconnect phone */
  451.         ASSERT(phone->state == IPC_PHONE_CONNECTED);
  452.         phone->state = IPC_PHONE_SLAMMED;
  453.         list_remove(&phone->link);
  454.  
  455.         spinlock_unlock(&phone->lock);
  456.     }
  457.  
  458.     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
  459.     ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
  460.     ipc_cleanup_call_list(&TASK->answerbox.calls);
  461.     spinlock_unlock(&TASK->answerbox.lock);
  462.    
  463.     /* Wait for all async answers to arrive */
  464.     while (1) {
  465.         /* Go through all phones, until all are FREE... */
  466.         /* Locking not needed, no one else should modify
  467.          * it, when we are in cleanup */
  468.         for (i = 0; i < IPC_MAX_PHONES; i++) {
  469.             if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
  470.                 atomic_get(&TASK->phones[i].active_calls) == 0)
  471.                 TASK->phones[i].state = IPC_PHONE_FREE;
  472.            
  473.             /* Just for sure, we might have had some
  474.              * IPC_PHONE_CONNECTING phones */
  475.             if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
  476.                 ipc_phone_hangup(&TASK->phones[i]);
  477.             /* If the hangup succeeded, it has sent a HANGUP
  478.              * message, the IPC is now in HUNGUP state, we
  479.              * wait for the reply to come */
  480.            
  481.             if (TASK->phones[i].state != IPC_PHONE_FREE)
  482.                 break;
  483.         }
  484.         /* Voila, got into cleanup */
  485.         if (i == IPC_MAX_PHONES)
  486.             break;
  487.        
  488.         call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT,
  489.             SYNCH_FLAGS_NONE);
  490.         ASSERT((call->flags & IPC_CALL_ANSWERED) ||
  491.             (call->flags & IPC_CALL_NOTIF));
  492.         ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
  493.        
  494.         atomic_dec(&TASK->active_calls);
  495.         ipc_call_free(call);
  496.     }
  497. }
  498.  
  499.  
  500. /** Initilize IPC subsystem */
  501. void ipc_init(void)
  502. {
  503.     ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL,
  504.         NULL, 0);
  505. }
  506.  
  507.  
  508. /** List answerbox contents.
  509.  *
  510.  * @param taskid    Task ID.
  511.  */
  512. void ipc_print_task(task_id_t taskid)
  513. {
  514.     task_t *task;
  515.     int i;
  516.     call_t *call;
  517.     link_t *tmp;
  518.    
  519.     spinlock_lock(&tasks_lock);
  520.     task = task_find_by_id(taskid);
  521.     if (task)
  522.         spinlock_lock(&task->lock);
  523.     spinlock_unlock(&tasks_lock);
  524.     if (!task)
  525.         return;
  526.  
  527.     /* Print opened phones & details */
  528.     printf("PHONE:\n");
  529.     for (i = 0; i < IPC_MAX_PHONES; i++) {
  530.         spinlock_lock(&task->phones[i].lock);
  531.         if (task->phones[i].state != IPC_PHONE_FREE) {
  532.             printf("%d: ", i);
  533.             switch (task->phones[i].state) {
  534.             case IPC_PHONE_CONNECTING:
  535.                 printf("connecting ");
  536.                 break;
  537.             case IPC_PHONE_CONNECTED:
  538.                 printf("connected to: %p ",
  539.                        task->phones[i].callee);
  540.                 break;
  541.             case IPC_PHONE_SLAMMED:
  542.                 printf("slammed by: %p ",
  543.                        task->phones[i].callee);
  544.                 break;
  545.             case IPC_PHONE_HUNGUP:
  546.                 printf("hung up - was: %p ",
  547.                        task->phones[i].callee);
  548.                 break;
  549.             default:
  550.                 break;
  551.             }
  552.             printf("active: %d\n",
  553.                 atomic_get(&task->phones[i].active_calls));
  554.         }
  555.         spinlock_unlock(&task->phones[i].lock);
  556.     }
  557.  
  558.  
  559.     /* Print answerbox - calls */
  560.     spinlock_lock(&task->answerbox.lock);
  561.     printf("ABOX - CALLS:\n");
  562.     for (tmp = task->answerbox.calls.next; tmp != &task->answerbox.calls;
  563.         tmp = tmp->next) {
  564.         call = list_get_instance(tmp, call_t, link);
  565.         printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d "
  566.             "Flags:%x\n", call, call->sender->taskid,
  567.             IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  568.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  569.             call->flags);
  570.     }
  571.     /* Print answerbox - calls */
  572.     printf("ABOX - DISPATCHED CALLS:\n");
  573.     for (tmp=task->answerbox.dispatched_calls.next;
  574.          tmp != &task->answerbox.dispatched_calls;
  575.          tmp = tmp->next) {
  576.         call = list_get_instance(tmp, call_t, link);
  577.         printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d "
  578.             "Flags:%x\n", call, call->sender->taskid,
  579.             IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  580.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  581.             call->flags);
  582.     }
  583.     /* Print answerbox - calls */
  584.     printf("ABOX - ANSWERS:\n");
  585.     for (tmp = task->answerbox.answers.next; tmp != &task->answerbox.answers;
  586.         tmp = tmp->next) {
  587.         call = list_get_instance(tmp, call_t, link);
  588.         printf("Callid:%p M:%d A1:%d A2:%d A3:%d Flags:%x\n", call,
  589.             IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  590.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  591.             call->flags);
  592.     }
  593.  
  594.     spinlock_unlock(&task->answerbox.lock);
  595.     spinlock_unlock(&task->lock);
  596. }
  597.  
  598. /** @}
  599.  */
  600.